The correct answer is: C. Bleeding can be increased by addition of calcium chloride.
Bleeding is the upward movement of water and cement paste to the surface of concrete. It is a common problem in concrete construction, and can lead to a number of defects, such as surface crazing, popouts, and honeycombing.
The amount of bleeding that occurs in a concrete mix is affected by a number of factors, including the water-cement ratio, the type and amount of aggregate, the admixtures used, and the curing conditions.
Lean mixes (mixes with a low water-cement ratio) tend to bleed more than rich mixes (mixes with a high water-cement ratio). This is because lean mixes have less cement paste, which means that there is more water available to bleed to the surface.
Pozzolanas and finer aggregates can help to reduce bleeding by absorbing water and reducing the amount of free water available to bleed. Calcium chloride, on the other hand, can increase bleeding by increasing the amount of free water in the mix.
Therefore, the statement “Bleeding can be increased by addition of calcium chloride” is incorrect.